Amino acid sequences directed against cellular receptors for viruses and bacteria

Abstract

The present invention relates to amino acid sequences that are directed against (as defined herein) human cellular receptors for viruses and/or bacteria such as e.g. NANOBODIES specifically recognizing hCD4, hCXCR4, hCCR5, hTLR4, human alphaV integrin, human beta3 integrin, human beta1 integrin, human alpha2 integrin, hCD81, hSR-BI, hClaudin-1, hClaudin-6 and hClaudin-9, as well as to compounds or constructs, and in particular proteins and polypeptides, that comprise or essentially consist of one or more such amino acid sequences. The amino acid sequences may be used to prevent human cell entry of HIV, HCV, adenoviruses, hantavirus, herpesvirus, echo-virus 1 and others.

The invention claimed is: 
     
       1. An isolated polypeptide comprising one or more VHH, humanized VHH or camelized VH that specifically bind CD4 and that inhibit HIV entry into a cell, wherein at least one VHH, humanized VHH or camelized VH consist essentially of 4 framework regions (FR1 to FR4, respectively) and 3 complementarity determining regions (CDR1 to CDR3, respectively), in which CDR1 is the amino acid sequence of SEQ ID NO: 287; CDR2 is the amino acid sequence of SEQ ID NO: 295; and CDR3 is the amino acid sequence of SEQ ID NO: 303. 
     
     
       2. The isolated polypeptide according to  claim 1  that specifically binds to hCD4 (SEQ ID NO: 268). 
     
     
       3. The isolated polypeptide of  claim 1 , that comprises two or more VHH, humanized VHH or camelized VH. 
     
     
       4. The isolated polypeptide of  claim 3 , that comprises two VHH, humanized VHH or camelized VH. 
     
     
       5. A nucleic acid or nucleotide sequence that encodes a polypeptide of  claim 1 . 
     
     
       6. An isolated host cell comprising the nucleic acid or nucleotide sequence of  claim 5 , and wherein the isolated host cell is not in a multicellular organism. 
     
     
       7. A composition comprising a polypeptide of  claim 1 . 
     
     
       8. The composition according to  claim 7  that further comprises at least one pharmaceutically acceptable carrier, diluent or excipient and/or adjuvant, and that optionally comprises one or more further pharmaceutically active polypeptides and/or compounds. 
     
     
       9. An isolated polypeptide of  claim 1 , wherein:
 (i) FR1 is the amino acid sequence of SEQ ID NO: 283 or an amino acid sequence that has at least 80% sequence identity with the amino acid sequence of SEQ ID NO: 283; 
 (ii) FR2 is the amino acid sequence of SEQ ID NO: 291 or an amino acid sequence that has at least 80% sequence identity with the amino acid sequence of SEQ ID NO: 291; 
 (iii) FR3 is the amino acid sequence of SEQ ID NO: 299 or an amino acid sequence that has at least 80% sequence identity with the amino acid sequence of SEQ ID NO: 299; and 
 (iv) FR4 is the amino acid sequence of SEQ ID NO: 307 or an amino acid sequence that has at least 80% sequence identity with the amino acid sequence of SEQ ID NO: 307. 
 
     
     
       10. An isolated polypeptide comprising two VHH, humanized VHH or camelized VH that specifically bind CD4 and that inhibit HIV entry into a cell, wherein each of the two VHH, humanized VHH or camelized VH consist essentially of 4 framework regions (FR1 to FR4, respectively) and 3 complementarity determining regions (CDR1 to CDR3, respectively), in which CDR1 is the amino acid sequence of SEQ ID NO: 287; CDR2 is the amino acid sequence of SEQ ID NO: 295; and CDR3 is the amino acid sequence of SEQ ID NO: 303. 
     
     
       11. An isolated polypeptide of  claim 10 , wherein:
 (i) FR1 is the amino acid sequence of SEQ ID NO: 283 or an amino acid sequence that has at least 80% sequence identity with the amino acid sequence of SEQ ID NO: 283; 
 (ii) FR2 is the amino acid sequence of SEQ ID NO: 291 or an amino acid sequence that has at least 80% sequence identity with the amino acid sequence of SEQ ID NO: 291; 
 (iii) FR3 is the amino acid sequence of SEQ ID NO: 299 or an amino acid sequence that has at least 80% sequence identity with the amino acid sequence of SEQ ID NO: 299; and 
 (iv) FR4 is the amino acid sequence of SEQ ID NO: 307 or an amino acid sequence that has at least 80% sequence identity with the amino acid sequence of SEQ ID NO: 307. 
 
     
     
       12. The isolated polypeptide according to  claim 1  or  10  that has an antiviral activity, expressed as IC50 measured in an HIV-1 infection assay, equal to or below 100 nM. 
     
     
       13. The isolated polypeptide according to  claim 1  or  10 , that has an antiviral activity, expressed as IC50 measured in an HIV-1 infection assay, equal to or below 50 nM. 
     
     
       14. The isolated polypeptide according to  claim 1  or  10 , that has an antiviral activity, expressed as IC50 measured in an HIV-1 infection assay, equal to or below 10 nM. 
     
     
       15. The isolated polypeptide according to  claim 1  or that has an antiviral activity, expressed as IC50 measured in an HIV-1 infection assay, equal to or below 1 nM. 
     
     
       16. An isolated polypeptide comprising the amino acid sequence set forth as SEQ ID NO: 311. 
     
     
       17. An isolated VHH, humanized VHH or camelized VH that specifically binds CD4, wherein said VHH, humanized VHH or camelized VH consists essentially of 4 framework regions (FR1 to FR4, respectively) and 3 complementarity determining regions (CDR1 to CDR3, respectively), in which CDR1 is the amino acid sequence of SEQ ID NO: 287; CDR2 is the amino acid sequence of SEQ ID NO: 295; and CDR3 is the amino acid sequence of SEQ ID NO: 303. 
     
     
       18. An isolated VHH, humanized VHH or camelized VH of  claim 17 , wherein:
 (i) FR1 is the amino acid sequence of SEQ ID NO: 283 or an amino acid sequence that has at least 80% sequence identity with the amino acid sequence of SEQ ID NO: 283; 
 (ii) FR2 is the amino acid sequence of SEQ ID NO: 291 or an amino acid sequence that has at least 80% sequence identity with the amino acid sequence of SEQ ID NO: 291; 
 (iii) FR3 is the amino acid sequence of SEQ ID NO: 299 or an amino acid sequence that has at least 80% sequence identity with the amino acid sequence of SEQ ID NO: 299; and 
 (iv) FR4 is the amino acid sequence of SEQ ID NO: 307 or an amino acid sequence that has at least 80% sequence identity with the amino acid sequence of SEQ ID NO: 307.